1. Field of the Invention
This invention is in the field of cameras, and more specifically those designed to be disposable.
2. Description of Prior Art
A recent innovation is to provide a camera which may be subsequently discarded after a single use. Such cameras may be used as a promotional item, or for use in a particular application. For example, insurance companies commonly require a photograph of the item to be insured prior to issuing a policy. Delays are thus often incurred because of the lack of availability of a camera and/or the time involved in having the film developed. It is therefore advantageous to have a camera easily mailed, instantly developing and which may be economically discarded rather than returned. Such a camera is disclosed in my abandoned U.S. patent application Ser. No. 124,270 filed on Nov. 23, 1987. The aforementioned camera included collapsible bellows for ease of shipment and developing means within the camera to allow the exposed film to be ejected from the camera in a developed state.
Additional prior cameras of interest include the camera disclosed in U.S. Pat. No. 3,712,198 issued to Nerwin. The Nerwin Patent discloses a camera having a film pack, telescoping bellows and a lens and shutter. Likewise, my U.S. Pat. No. 4,518,235 discloses a set of pressurized rollers mounted within the camera for applying pressure to the exposed film, thereby spreading the developing medium across the exposed film prior to ejectment. Earlier cameras having collapsible telescopic bellows include the U.S. Pat. No. 524,142 issued to Hegelein; U.S. Pat. No. 3,668,992 issued to Harvey; U.S. Pat. No. 1,061,115 issued to Pickard; U.S. Pat. No. 2,109,807 issued to Tagima; U.S. Pat. No. 4,268,149 issued to Ettischer; and, U.S. Pat. No. 3,665,832 issued to Harvey.
When producing a low cost throw-away camera typically from paper or plastic material, a frequent problem is to control the focal distance between the lens and the film when the bellows is in the erect state. The problem of controlling the focal length is magnified when the bellows is repeatedly collapsed and erected which depends upon the number of frames in the film Packet and the number of times the camera is stored and subsequently used. I have therefore devised a camera utilizing the film developing pressure means disclosed in my aforementioned patent within a new camera structure including a collapsible bellows which automatically insures proper setting out the focal distance. The bellows utilizes a plurality of adjacent truncated annular walls integrally connected together by a hinged structure. Collapsible annular walls have previously been known such as shown in U.S. Pat. No. 4,492,313 issued to Touzani for a collapsible soda drink bottle; however, the particular design of such a bellows in combination with a camera as disclosed herein is particularly unique and novel.